when这个英语单词是什么意思?

when这个英语单词是什么意思?

when
[hwen]
adv.
什么时候
在那时, 其时
conj.
在…时, 当时
如果, 要是
When the weather is good, I usually go to the country.
若是天气好的话, 我总是到乡下去。
既然, 考虑到
pron.
什么时候
那时

美国传统词典[英英]
when
when
AHD:[hwãn, wãn]
adv.
At what time:
When will we leave?
conj.
At the time that:
in the spring, when the snow melts.
As soon as:
I'll call you when I get there.
Whenever:
When the wind blows, all the doors rattle.
During the time at which; while:
when I was young, I was sick all the time.
Whereas; although:
She stopped short when she ought to have continued.
Considering that; if:
How can he get good grades when he won't study?
pron.
What or which time:
Since when has this been going on?
n.
The time or date:
Have they decided the where and when?

I know the proverb, but does the dog know the proverb, too?"

当。。。的时候